Precisely adjustable optical device having vibration and temperature stability

ABSTRACT

An adjustable optical device including an optical element, a housing having an adjusting post fixed thereto, the optical element mounted to the housing, the housing adjusting post having a plane of movement, and an adjustment mechanism, the housing flexibly connected to the adjustment mechanism, the adjustment mechanism comprising a moving adjusting member in sliding engagement with the housing adjusting post, one of the adjusting member and the housing adjusting post comprising a wedge. The housing adjusting post is urged into movement in its plane of movement in response to relative movement between the adjusting member and the adjusting post, whereby the orientation of the optical element relative to the adjusting mechanism is adjusted by movement of the moving adjusting member.

CROSS-REFERENCE TO RELATED APPLICATION

This is a Divisional Application of patent application Ser. No.09/432,363, filed Nov. 3, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to optical devices which include anadjustable optical element which may be adjusted with high precision,and in particular to such optical devices which are adjustable about twoperpendicular axes and are vibration and temperature stable.

2. Description of the Related Art

Adjustable optical devices may be used in relay optics systems whichdivide and coregister multiple optical beams. In some cases, suchsystems must be accommodated in an apparatus having limited packagespace, for instance, a satellite. A relay optics system for a satelliteis described in U.S. Pat. No. 4,801,202, entitled “Method and ApparatusFor Radiometer Star Sensing”, the disclosure of which is expresslyincorporated herein by reference. This patent describes an earthscanning radiometer instrument which uses a mirror to collect radiation,and transfers an image of the radiation onto the surface of a detectorwhich converts the incident radiation into an electrical signal, whichis then converted into a digital image. To provide images across a broadspectrum of radiation the collected radiation is divided and directedonto several detector surfaces sensitive to discrete wavelengths. Suchdivision is referred to in the art as relay optics. It is to beunderstood that, in the context of the following discussion, the term“optical” does not relate solely to the visible light spectrum; rather,the term relates to radiation across a broad band of wavelengths,including those on which visible light is transmitted.

Proper digital imaging requires that the divided detectors be alignedwith one another, i.e., coregistered. Relay optics systems requirephysical space and contribute mass to the structure on which they areinstalled. In particular, where that structure is a satellite, theshortcomings of previous relay optics systems are, in part, associatedwith their package requirements and weight. Further, accessibility tothe optical elements which comprise the system, once installed, is oftendifficult. The mechanical motions associated with adjustment of theoptical elements are very fine, and the movements associated therewithmust be free of backlash. In previous relay optics systems, complexmechanical mechanisms are necessary to facilitate adjustment of thedivided beams onto the coregistered detectors. Moreover, the elementsmust not move after being properly adjusted, and certainly not afterlaunch of the satellite. Further, the adjustment mechanism is subjectedto substantial vibration, particularly during launch, and once in orbitis subjected to temperatures which may vary in a range from about−20° C.to about 70° C. The vibratory inputs and temperature variations to whichprevious adjustment mechanism are subjected may affect proper adjustmentof the optical element.

Moreover, the adjustment mechanism itself may contribute significantlyto the relay optics system, and thus to the weight of, and the packagespace which must be accommodated by, the satellite. Further, someearth-bound communication systems may have limited package space inwhich a relay optics system must be accommodated.

Means for providing an improved, easily yet finely adjustable opticaldevice and associated adjustment mechanism for a relay optics system,which is small in size, lightweight, vibration and temperature stable,and capable of high-resolution adjustment to produce a coregisteredimage is highly desirable, particularly for use in satellite-based andsome earth-bound relay optics systems.

SUMMARY OF THE INVENTION

The present invention provides a lightweight, precisely adjustableoptical device which may be used in a relay optics system which dividesand coregisters multiple optical beams and includes a flexure mechanismto produce high-resolution adjusting movements of the optical element.The device is lightweight and occupies limited volume, making itsuitable for spaceflight use. The device provides means for locking theadjusted optical element into place, thereby providing vibrationstability, and is comprised of materials having common coefficients ofthermal expansion, thereby providing thermal stability.

In one embodiment, the movement between the housing, to which theoptical element is mounted, and the base portion, which is attached tothe satellite chassis, is substantially frictionless.

In another embodiment, the adjusting device is separable from theoptical device, the latter of which is attached to the satellitechassis; the optical element is locked in position after adjustment. Theadjusting device is disengaged from the optical device after locking theoptical element in position, and does not fly with the satellite.

The present invention provides an adjustable optical device including anoptical element, a housing having an adjusting post fixed thereto, theoptical element mounted to the housing, the housing adjusting posthaving a plane of movement, and an adjustment mechanism. The housing isflexibly connected to the adjustment mechanism, which includes a movingadjusting member in sliding engagement with the housing adjusting post.One of the adjusting member and the housing adjusting post includes awedge, and the housing adjusting post is urged into movement in itsplane of movement in response to relative movement between the adjustingmember and the adjusting post, whereby the orientation of the opticalelement relative to the adjusting mechanism is adjusted by movement ofthe moving adjusting member.

The present invention also provides an adjustable optical deviceincluding a housing having a substantially spherical outer surface, anoptical element disposed within the housing, a base having asubstantially spherical inner surface, the base inner surface overlyinga portion of the housing outer surface, the base inner surface and thehousing outer surface frictionally engaged, and a cover having asubstantially spherical inner surface, the cover inner surface overlyinga portion of the housing outer surface, the cover inner surface and thehousing outer surface frictionally engaged. The housing is disposedbetween the base and the cover, and the cover is attached to the base.Frictional engagement between the base and the housing, and the coverand the housing, has a first level and a second level. The first levelis substantially less than the second level, whereby relative movementbetween the housing and the base is resisted yet permitted at the firstfrictional engagement level. Relative movement between the housing andthe base is prevented at the second frictional engagement level.

The present invention also provides an adjustable optical deviceincluding an optical element and a housing, the optical element disposedwithin the housing. Also included is a base having a substantiallyspherical inner surface. The housing has a substantially spherical outersurface engaged with the base substantially spherical inner surface. Thehousing is provided with a driven surface, and has a tilt axis and aroll axis about which the orientation of the housing relative to thebase is adjusted. An adjustment device has an operating positionrelative to the base, and includes a moving adjusting mechanism whichincludes a driving surface, the driven and driving surfaces engaged inthe operating position. The adjusting mechanism includes a leveroperatively connected to the driving surface, the lever having twosubstantially perpendicular degrees of movement. Movement of the housingabout one of its tilt and roll axes is in response to movement of thelever along one of its degrees of movement.

The present invention further provides an adjustable optical deviceincluding an optical element, a base, and a housing, the optical elementmounted in the housing. The housing is coupled to the base and has atleast one degree of movement relative to the base, whereby theorientation of the optical element relative to the base is adjusted bythe movement of the housing in the at least one degree of movement. Alsoincluded is an adjustment device detachably connected to the base andhaving a moving adjusting mechanism. When the adjustment device isconnected to the base, the adjusting mechanism is operatively connectedto the housing to move the housing in its at least one degree ofmovement in response to movement of the adjusting mechanism. The housingis selectively locked to the base and remains selectively locked to thebase when the adjustment device is detached from the base.

The present invention also provides an adjustable optical deviceincluding a housing having a spherical outer surface, the housing outersurface having a radius of curvature, an optical element mounted withinthe housing, a base having a spherical inner surface, the base innersurface having substantially the same radius of curvature as the housingouter surface, and a cover having a spherical inner surface, the coverinner surface having substantially the same radius of curvature as thehousing outer surface. The cover and the base inner surfaces are infrictional engagement with the housing outer surface and are moveablerelative to each other to thereby selectively frictionally clamp thehousing against movement relative to the base and the cover.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1a is a perspective view of a first embodiment of an adjustableoptical device and its associated adjustment device according to thepresent invention, shown interconnected through a mounting plate towhich the inventive optical device is attached;

FIG. 1b is an exploded view of the assemblage shown in FIG. 1;

FIG. 1c is a perspective view a second embodiment of an adjustableoptical device according to the present invention;

FIG. 2 is a rear perspective view of the adjustable optical device ofFIG. 1;

FIG. 3a is an exploded view of the adjustable optical device of FIG. 1;

FIG. 3b is an exploded view of the spherical housing and optical elementwhich comprises the optical device of FIG. 1;

FIG. 4 is a an exploded view of the adjustment device of FIG. 1;

FIG. 5a is a first cross sectional side view of the assemblage shown inFIG. 1;

FIG. 5b is a second cross sectional side view of the assemblage shown inFIG. 1;

FIG. 6a is a first cross sectional side view of a third embodiment of anadjustable optical device and its associated adjustment device accordingto the present invention, shown interconnected through a mounting plateto which the inventive optical device is attached;

FIG. 6b is a second cross sectional view of the assemblage shown in FIG.6a;

FIG. 7 is a lower front perspective view of a fourth embodiment of anadjustable optical device according to the present invention;

FIG. 8a is an upper rear perspective view of the adjustable opticaldevice of FIG. 7;

FIG. 8b is an exploded view of the adjustable optical device of FIG. 8a;

FIG. 9a is a lower rear perspective view of the adjustable opticaldevice of FIG. 7;

FIG. 9b is an exploded view of the adjustable optical device of FIG. 9a;

FIG. 10a is a side view of the adjustable optical device of FIG. 7;

FIG. 10b is a front view of the adjustable optical device of FIG. 7;

FIG. 10c is a bottom view of the adjustable optical device of FIG. 7;

FIG. 11 is a cross sectional rear view of the adjustable optical deviceof FIG. 10a along line 11—11;

FIG. 12 is a cross sectional side view of the adjustable optical deviceof FIG. 10b along line 12—12;

FIG. 13 is a cross sectional front view of the adjustable optical deviceof FIG. 10c along line 13—13;

FIG. 14 is a cross sectional side view of the adjustable optical deviceof FIG. 10c along line 14—14; and

FIG. 15 is a cross sectional, fragmentary side view of the adjustableoptical device of FIG. 10c along line 15—15.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate different embodiments of the present invention, in severalforms, and such exemplifications are not to be construed as limiting thescope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1a and 1 b, there is shown a first embodiment of anadjustable optical device and its associated adjustment device accordingto the present invention. Adjustable optical device 20 is secured tomounting plate 22 of satellite chassis 24. Chassis 24 may have aplurality of devices such as device 20 attached to it, each dedicated toconveying radiation of a certain wavelength to a detector (not shown).Device 20 includes movable optical element 26 which receives light orother radiation along input axis 28. Optical element 26 has reflectivesurface 27 and may be a fold mirror or a beam splitter, and has anoutput axis 30 along which light is directed to the detector or toanother optical device mounted to the chassis. If optical element 26 isa beam splitter, only a portion of the light received along input axis28 will be directed along output axis 30; another portion of the light,having a different wavelength, will pass through the beam splitter alongoutput axis 28 a which is substantially collinear with input axis 28.Light directed along axis 28 a is received by a detector or by anotheroptical device.

Optical element 26 is adjustable about roll axis 32, in the directionsindicated by arrow R, and about tilt axis 34, in the directionsindicated by arrow T. As shown, roll axis 32 is collinear with inputaxis 28, but these are individual axes which may be slightly displacedrelative to one another. Roll and tilt axes 32, 34 intersect at opticalcenter 35 (FIG. 3b) of optical element 26, which lies on surface 27.Optical device 20 may be adjusted generally along the direction ofoutput axis 30 by means of shim(s) 36 placed between optical device 20and mounting plate 22. It is envisioned that the range of adjustment ofthe optical center generally along the axis of output axis 30 whichshould be accommodated with device 20 is on the order of ±0.002 inch,with shim(s) 36 individually providing a linear resolution of about0.001 inch.

Referring to FIG. 1b, fasteners 38 extend through holes provided inmounting plate 22 and shim 36, and are threadedly received in tappedholes 40 (FIG. 2) provided on “bottom” surface 41 of optical device base42, thereby attaching optical device 20 to satellite chassis 24.Alignment pins 44 extend from bottom surface 41 in directions generallyparallel with output axis 30 and project through holes provided thereforin shim 36 and mounting plate 22, thereby substantially aligning opticaldevice 20 to the satellite chassis. Pins 44 are used for aligning theadjustment device to the optical device during adjustment of the opticalelement, as will be described further hereinbelow.

Referring to FIGS. 3a and 3 b, optical element 26 is disposed in housing46 which has openings 48 and 50 through which input axis 28 and outputaxis 30 respectively extend. Housing 46 has spherical outer surface 52which is round to within a tolerance of 0.0001 inch. The center ofcurvature of spherical outer surface 52 is coincident with opticalcenter 35 of optical element 26. Note that roll axis 32 and tilt axis 34are fixed relative to optical element 26, and optical element 26 isfixed relative to housing 46; thus, adjustment of housing 46 about thetilt and roll axes will likewise adjust optical element 26 about theseaxes. Housing 46 is provided with stem 54 which projects from sphericalsurface 52 and is provided with frustoconical driven surface 56. Stem 54extends through hole 58 provided in spherical inner surface 60 of base42. Surface 60 is also round to within 0.0001 inch. Spherical outersurface 52 and spherical inner surface 60 have a common nominal radiusof curvature, and are in surface-to-surface contact with one another.Housing 46 is disposed between base 42 and cover 62. Cover 62 isprovided with opening 64 through which output axis 30 extends, and hasspherical inner surface 66 which is round to within 0.0001 inch and alsohas a center of curvature common to surfaces 52 and 60. Surface 66 hassurface-to-surface contact with housing surface 52. Opposite side facesof base 42 and cover 62 are respectively provided with scallops 68, 70and 72, 74, as shown in FIG. 3a. These scallops partially defineopenings in device 20 through which input axis 28 and output axis 28 aextend.

Disposed between base 42 and cover 62, on opposite radial sides ofhousing 46 are spacer member 76 and stop member 78. Spacer member 76 isnearly identical with stop member 78 except that it is slightly thickerin a direction generally along output axis 30. Fasteners 80, 82, 84 and86 extend through holes provided in base 42, spacer member 76 or stopmember 78, and cover 62. These fasteners are threadedly received incover holes 88. Upon initial assembly of device 20, fasteners 80 and 82,which extend through spacer member 76, are tightened to a final torque,and spacer member 76 is placed in compression between base 42 and cover62. Fasteners 84 and 86, however, which extend through stop member 78,are not so torqued, and stop member 78 is not under compression betweenbase 42 and cover 62. In this state of assembly, surface-to-surfacecontact, and a light frictional engagement level exists between housingsurface 52 and surfaces 60 and 66 of the base and cover, and a smallgap, on the order a few ten thousands of an inch, may exist between anaxially facing side of stop member 78 and the adjacent, axially facingside of base 42 or cover 62. In this state of light frictional contact,housing 46 is not clamped between the base and the cover, and itsadjustment about roll axis 32 and tilt axis 34 is facilitated bymovement of stem 54. Movement is imparted to stem 54 by exertion of aforce against driven surface 56 through the adjustment device, asfurther explained below. For now, suffice it to say that movement ofstem 54 provides adjusting movement of optical element 26 about the rolland tilt axes.

Once the desired alignment of the optical element 26 is achieved,fasteners 84 and 86 are tightened to a final torque, and stop member 78is placed in compression between base 42 and cover 62. In this state,cover 62 is slightly flexed, and housing 46 is clamped between theinterfacing surfaces of the base and cover. Surface-to-surface contactbetween surface 52 and surfaces 60 and 66 is maintained in this clampedstate, but a higher level of frictional engagement therebetween isachieved, and movement of the housing relative to the base and cover isprevented, even during periods of the device undergoing substantialvibration, such as may be experienced during a rocket launch. Thus, theclamped interface between the spherical outer surface of housing 46 andthe spherical inner surfaces 60 and 66 of the base and cover contributeto the vibration stability of the inventive adjustable optical device.

Referring now to FIG. 3b, it can be seen that housing 46 is comprised offirst and second interfitted hemispherical housing portions 90 and 92,respectively, with optical element 26 mounted in a cavity 93 formed insecond housing portion 92. Second housing portion 92 is also providedwith opening 94 through which output axis 28 a extends (should opticalelement 26 happen to be a beam splitter). Stem 54 is provided withthreaded portion 100 which is received in tapped hole 102 provided insecond housing portion 92. The first and second housing portions areattached together by means of a plurality of fasteners 96, the heads ofwhich are recessed below outer spherical surface 52. Proper alignment ofthe first and second housing portions is ensured through alignment pins97 which extend from second housing portion 92 and are received withinmating alignment holes provided in first housing portion 90. Withincavity 93, optical element 26 rests on a resilient surface(s) of asuitable material such as rubber which maintains the proper orientationof surface 27 relative to the spherical center of housing 46 duringthermal expansion and contraction of housing 46 relative to opticalelement 26. The resilient material may be in the form of a plurality ofpads 98, as shown. Resilient pads 98 retain optical element 26 in itsproper location relative to housing 46 during and after periods ofsubstantial vibration, and contribute to the vibration stability of theinventive device.

Housing 46, base 42, cover 62, spacer member 76, stop member 78, andshim(s) 36 (if any) are all made of a common material, such as aluminum,for example, or materials having a common coefficient of thermalexpansion, thus allowing each of these components to expand and contractto a similar extent in response to variations in temperature withoutaltering the adjustment of the optical element about the roll and tiltaxes, or relative to mounting plate 22, thereby providing a thermallystable device. Fasteners 80, 82, 84, 86 and 96 may be made of aluminumor brass, or materials having a substantially similar coefficient ofthermal expansion to that of the material(s) of housing 46, base 42,cover 62, spacer member 76 and stop member 78. Further, satellitechassis 24 may be made of a material having a coefficient of thermalexpansion which is substantially similar to that of the inventivedevice's components.

FIG. 1c illustrates a second embodiment of an adjustable optical deviceaccording to the present invention. Adjustable optical device 20 acomprises base 42 a which provides a plurality of inner sphericalsurfaces 60 which interface with a plurality of housings 46 as describedabove, each containing an optical element 26. Rather than individualattachment of a plurality of bases 42 to the chassis, as shown in theexample of a satellite in FIG. 1b, a single base 42 a may be attached tothe chassis, thereby simplifying assembly. The material of base 42 a isthe same as used in base 42, and the remaining componentry of device 20a is as described above with regard to device 20. Adjustable opticaldevice 20 a, which is not shown attached to its associated chassis inFIG. 1c, receives radiation input along input axes 28, and directs aplurality of radiation output from the device along a plurality ofoutput axes 30 in the manner described herein above. Notably, eachoptical element 26 of device 20 a is independently adjustable in thesame manner, and using the same adjustment device, as the opticalelement 26 of device 20 is.

Referring now to FIGS. 1 and 4, there is shown adjustment device 104comprising body 106, front plate 108, which is attached to body 106 byfasteners 109, and rear plate 110, which is attached to body 106 byfasteners 111. As mentioned above, adjustment device 104 may be usedwith adjustable optical device 20 or 20 a. Adjustment device 104includes an adjustment mechanism comprising lever 112, one end of whichis provided with receptacle portion 113 within which is frustoconicaldriving surface 114, against which frustoconical driven surface 56 isengaged during adjustment. Adjacent receptacle portion 113, the exteriorof lever 112 is provided with flange 116. Abuttingly disposed betweenflange 116 and the interior, annular facing surface of front plate 108is disposed compression spring 118, which urges flange against surface119 of body 106. The portion of lever 112 on the side of flange 116which is opposite receptacle portion 113 extends into cavity 117 formedthrough body 106.

Lever 112 is provided with longitudinal bore 131 (FIGS. 5a, 5 b) throughwhich extends screw 152. Screw 152 is temporarily threadedly engagedwith tapped hole 154 in stem 54 while adjustment device 104 is engagedwith optical device 20, 20 a, to retain the adjustment device to theoptical device during adjusting procedures and to ensure properengagement of respective frustoconical driving and driven surfaces 114and 56. The head of screw 152 is accessed through hole 156 in rear plate110.

The adjustment mechanism further comprises springs 120 and 122 whichextend from cavity 117 through holes provided in the side of body 106and abut retainer plate 124. Retainer plate 124 is attached to body 106by means of fasteners 126. Springs 120 and 122 engage portion 127 oflever 112. Portion 127 includes counterbores 129 into which an end ofeach spring 120, 122 are disposed. Springs 120 and 122 urge leverportion 127 away from retainer plate 124, and lever 112 pivots aboutoptical center 35 in response to movement of portion 127. First andsecond lead screws 128, 130, respectively, extend through cavity 117alongside lever portion 127. First and second wedges 132 and 134 aredisposed in cavity 117 and are respectively threadedly received on leadscrews 128 and 130. Engagement surfaces 135, 136 of wedges 132, 134,respectively, faces directions which are substantially perpendicular toeach other and slidably engage lever portion 127. Springs 120 and 122urge lever portion 127 into sliding contact with engagement surface 136of wedge 134 and engagement surface 135 of wedge 132. Rotation of thelead screws individually imparts movement of the wedges along the lengthof lever portion 127, thereby inducing pivoting motion to lever 112.

FIG. 5a shows a section generally along a plane in which output axis 30lies and which is normal to roll axis 32; FIG. 5b shows a sectiongenerally along a plane in which output axis 30 lies and which is normalto tilt axis 34. Referring to FIGS. 5a and 5 b in particular, it can beseen that generally cylindrical boss portion 144 of front plate 108 isreceived in round hole 146 provided in mounting plate 22. A stepprovided on boss portion 144 is seated against the facing surface offront plate 108, and in this position adjustment device 104 is seatedonto mounting plate 22 and in its operating position relative to base 42of optical device 20. Alignment pins 44, which extend from base bottomsurface 41 and through mounting plate 22, are received in matingalignment holes 148 provided in front plate 108, thereby properlyangularly aligning adjusting device 104 to optical device 20. Asmentioned above, adjustment device 104 is temporarily attached, in itsoperating position, to adjustable optical device 20, 20 a throughengagement of screw 152 in hole 154 of stem 54. When adjustment device104 is held in its operating position, driven surface 56 of opticaldevice 20 is engaged with driving surface 114 of lever receptacle 113.It can now be readily understood that, with driving and driven surfaces114 and 56 so engaged, pivoting motion of lever 112 relative to theremainder of adjustment device 104 (and relative to optical device 20)in response to movement of wedges 132, 134 along their respective leadscrews will cause housing 46 to be rotated about one or both of its rolland tilt axes. Rotation of lead screw 128 imparts movement to opticalelement 26 about roll axis 32. Rotation of lead screw 130 impartsmovement to optical element 26 about tilt axis 34.

Ends 138 of the lead screws extend through rear plate 110 and havefitted thereon knobs 140. Knobs 140 are manually rotated and impartrotation to lead screws 132 and 130. The surface of each of knobs 140adjacent the axially facing exterior surface of rear plate 110 isprovided with a plurality of circumferentially distributed detents whichinteract with a spring-biased balls (not shown) fitted to rear plate 110to provide a tactile indication of incremental angular movement of thelead screws. Detents 142 thus give the operator adjusting knobs 140 anindication of the angle through which the knob has been rotated betweendetents. Knob 140 may be provided with detents at, for example, 30°increments. The number of detent positions felt correspond to aparticular angular adjustment (e.g., a certain number of microradians)of optical element 26 about the tilt or roll axis associated with thatknob. Optical element 26 has a range of motion about its roll axis ofapproximately ±20 milliradians (mrad), and the inventive adjustmentdevice provides the optical element with approximately 0.1 mrad ofangular resolution thereabout. Optical element 26 has a range of motionabout its tilt axis of approximately ±10 mrad, and the inventiveadjustment provides the optical element with approximately 0.05 mrad ofangular resolution thereabout.

Once the desired position of the optical element relative to satellitechassis 24 has been achieved through manipulation of knobs 140,fasteners 84 and 86 are torqued, thereby placing stop member 78 incompression, and tightening the interface between housing outer surface52, base inner surface 60, and cover inner surface 66. Once fasteners 84and 86 are tightened, relative movement between housing 46 and theremainder of optical device 20 is prevented, and adjustment device 104may be removed from its operating position by merely disengaging screw152 from hole 154 and separating the adjustment device from the opticaldevice. Each of the plurality of optical devices 20 mounted on satellitechassis 24 may be adjusted in turn by a single adjustment device 104.Because adjusting device 104 is detachable, the weight of the satellitein its flying configuration does not include the adjusting device.

Referring now to FIGS. 6a and 6 b there is shown a third embodiment ofan optical device 20′ and associated adjustment device 104′ according tothe present invention. FIG. 6a corresponds closely to FIG. 5a, and FIG.6b corresponds closely to FIG. 5b. Between the first, second and thirdembodiments, identical elements are identically referenced; elements ofthe third embodiment which functionally correspond to elements of thefirst embodiment are identified with primed, corresponding referencenumbers. Adjustable optical device 20′ is identical to device 20 exceptthat instead of having stem 54, second housing portion 92′ is providedwith a cavity 150 having frustoconical driven surface 56′ which, whenadjustment device 104′ is in its operating position, is engaged withdriving surface 114′ of lever 112′, which has no receptacle portion orscrew 152 extending longitudinally therethrough. Other portions of lever112′ and device 104′ are otherwise identical to the above-describedfirst embodiment. Movement of lever 112′ in response to movement ofwedge 132 or 134 induces rotation of optical element 26 about its tiltor roll axis, respectively. As described above, once the desiredorientation of housing 46′ relative to satellite chassis 24 has beenobtained, fasteners 84, 86 are torqued, bringing stop member 78 intocompression and providing a second level of friction engagement betweenouter housing surface 52′ and the adjacent spherical inner surfaces ofbase 42 and cover 62.

FIGS. 7-14 depict various views of a fourth embodiment of an adjustableoptical device according to the present invention. Adjustable opticaldevice 160 comprises base 162 and adjusting mechanism 164 which arefixed together by means of fasteners 166. A plurality of optical devices160 may be arranged on and attached to a satellite chassis which issimilar to that described above or to an earth-bound relay optics systemchassis (not shown).

Optical device 160 comprises optical element 168, which may be a foldmirror or beam splitter, as described above, and which has reflectiveoptical surface 170. Radiation or other light is received onto opticalsurface 170 along input axis 172 and is directed away from surface 170along output axis 174 toward another optical device or a detector (notshown). If optical element 168 is a beam splitter, a portion of thelight received along input axis 172 passes through the optical elementand continues along output axis 172 a toward a detector or anotheroptical element. Roll axis 176 and tilt axis 178, which areperpendicular, intersect on optical surface 170 at its optical center180. The roll and tilt axes are fixed relative to the device, asdescribed above, and the optical element is rotated in the directionsindicated by arrow T about the tilt axis, or rotated in the directionsindicated by arrow R about the roll axis (FIG. 8b). As shown, roll axis176 is collinear with input axis 172, but these are individual axeswhich may be slightly displaced relative to one another.

Optical element 168 is fixed to optical tray 182 which is an integralportion of housing 184. Frame 186 is fastened over optical element 168and attached to optical tray 182 by means of a plurality of fasteners188. As shown in FIGS. 8a and 8 b, housing 184 is provided with hole 190through which output axis 172 a extends, should optical element 168 be abeam splitter.

Optical device 160 further comprises intermediate member 192 disposedbetween housing 184 and base 162. Housing 184 is flexibly connected tointermediate member 192 by means of first flexure mechanism 194 having afirst portion 194 a and a second portion 194 b located on opposite sidesof housing 184 as shown. Flexure mechanism 194 comprises first flexureelements 196 a, 196 b, which comprise its first portion 194 a, and firstflexure elements 196 c and 196 d, which comprise its second portion 194b. First flexure elements 196 are each flat and bend in planes which arenormal to tilt axis 178. Notably, first and second portions 194 a and194 b may respectively be comprised of additional first flexure elements196; it is envisioned however, that within each portion 194 a and 194 b,first flexure elements 196 will be oriented such that extensions oftheir individual longitudinal axes intersect at a common point. Firstflexure elements 196 may be an integral part of housing 184 and/orintermediate member 192. Alternatively, first flexure elements 196 maybe individual flexure elements which are attached to both housing 184and intermediate member 192. As shown, first flexure elements 196 areintegral to and extend between portions of both intermediate member 192and housing 184. Also, as shown, intermediate member 192 comprises aplurality of interconnected components. What ultimately distinguishesthe housing from the intermediate member, however is the flexibleconnection therebetween, as through first flexure elements 196.

Referring to FIG. 8b, fixed to housing 184 and extending throughintermediate member 192 and base 162 is housing adjusting post 198.Housing adjusting post 198 has a plane of movement in which arrow 200lies, and tilt axis 178 is normal to this plane of movement. Themovement of housing adjusting post 198 in the directions indicated byarrow 200 is about tilt axis 178. Were intermediate member 192 fixed,movement of housing adjusting post 198 in the directions of arrow 200would induce rotation of optical element 168 about tilt axis 178 againstthe resilient bias of first flexure mechanism 194.

Intermediate member 192, however, is flexibly connected to base 162 bymeans of second flexure mechanism 202, which comprises first portion 202a and second portion 202 b located on opposite sides of the intermediatemember as shown. First portion 202 a of second flexure mechanism 202comprises second flexure element 204 a, and second portion 202 b ofsecond flexure mechanism 202 comprises second flexure element 204 b.Each of flexure elements 204 a and 204 b are substantially flat and maybe integral with intermediate member 192 and/or base 162. Alternatively,these second flexure elements may be individually attached to theintermediate member and the base.

Fixed to intermediate member 192 and extending through base 162 isintermediate member adjusting post 206, which has a plane of movement inwhich arrow 208 (FIG. 8b) lies. The plane of movement of intermediatemember adjusting post 206 is normal to roll axis 176 and movement ofpost 206 along the directions indicated by arrow 208 is about roll axis176. Intermediate member adjusting post 206 is provided with cavity 210which extends along its length. Cavity 210 has opposed side walls 214and 216 which slidably engage the interfacing side surfaces of housingadjusting post 198, which is located within cavity 210. Thus it can beunderstood that movement of intermediate member adjusting post 206 alongthe directions indicated by arrow 208 induces movement of housingadjusting post 198 along the directions indicated by arrow 208 as well.In other words, the plane of movement of housing adjusting post 198pivots about roll axis 176 with intermediate member adjusting post 206.Further, it is to be understood that at any position of intermediatemember adjusting post 206 in its plane of movement, housing adjustingpost 198 may be moved in its respective plane of movement in thedirections indicated by arrow 200. Movement of housing adjusting post198 in its plane of movement (normal to tilt axis 178) adjusts opticalelement 168 about tilt axis 178, whereas movement of intermediateadjusting post 206 in its plane of movement (normal to roll axis 176)adjusts optical element 168 about roll axis 176. It can thus be readilyunderstood that adjustment of the optical element is accomplished byurging the two adjusting posts in their respective planes of movement,along arrows 200 or 208, against the resilient biasing forces of thefirst or second flexure mechanisms, which tend to orient adjusting posts198 and 206 into a neutral position along axis 212, which extends in adirection generally perpendicular to the roll and tilt axes andgenerally parallel with output axis 174 (FIG. 8b).

Adjusting mechanism 164 comprises body 218 provided with cross-shapedcavity 220 formed by four recesses 221 a-d extending radially from thecenter of the cavity, into which adjusting posts 198 and 206 extendalong axis 212. The four recesses form equal length “arms” of the“cross” in planes taken along the axial direction of body 218. Referringto FIGS. 11-14, it can be seen that the lengths of these arms vary withthe distance along the length of body 218, as the radially outer wallsof these four recesses slope outwardly from the “bottom” of body 218towards base 162. Slidably disposed within recess 221 a is first wedge222; slidably disposed within recess 221 b is second wedge 224; slidablydisposed within recess 221 c is third wedge 226; and slidably disposedwithin recess 221 d is fourth wedge 228. Each wedge is in slidingengagement with the three flat walls forming its respective recess. Oneof the three flat walls forming each recess 221 a-d is itself defined byan associated wedge-shaped locking member 229 a-d which is integral tobody 218 and attached at one end to the remainder of body 218 byresilient, deflecting portion 256 a-d; FIG. 15 illustrates therepresentative structure of member 229 d and its resilient, deflectingportion 256 d. As will be further discussed hereinbelow, once opticalelement has been properly adjusted, wedges 222, 224, 226 and 228 arelocked within their respective recesses 221 a-d to prevent inadvertentmovement thereof, which may alter the adjusted position of the opticalelement.

Referring to FIGS. 8b, 9 b, 12 and 14, first wedge 222 has angledengagement surface 230 which interfaces curved projecting surface 238 ofhousing adjusting post 198. Similarly, third wedge 226 has angledengagement surface 234 which interfaces curved projecting surface 242 ofhousing adjusting post 198.

Referring to FIGS. 8b, 9 b, 11 and 13, second wedge 224 has angledengagement surface 232 which interfaces curved projecting surface 240 ofintermediate member adjusting post 206. Similarly, fourth wedge 228 hasangled engagement surface 236 which interfaces curved projecting surface244 of intermediate member adjusting post 206.

Wedges 222, 224, 226 and 228 are respectively threadedly disposed onlead screws 246, 248, 250 and 252 which extend into cavity 220 throughholes 253 which extend through “bottom” wall 254 of body 218. Leadscrews 246, 248, 250 and 252 are disposed within cavity 220 at an anglerelative to axis 212, each generally parallel with the outer radial wallof the cavity recess along which it extends. The wedges of each opposedpair of wedges (first wedge 222 and third wedge 226; and second wedge224 and fourth wedge 228) are located at opposite axial ends of cavity220 and are driven toward each other as they are brought into contactwith the curved projecting surface of the adjusting arms whichinterfaces with its respective engagement surface. This aspect is bestseen in FIGS. 11-14: For example, note that opposed pair of wedges 224and 228 are shown in FIG. 11 to be located at opposite axial ends ofcavity 220, with wedge 228 located above wedge 224 in the drawing.Rotation of lead screw 252 in one direction will draw wedge 228downward, towards curved projecting surface 244 of intermediate memberadjusting post 206; similarly rotation of lead screw 250 in onedirection will force wedge 224 upward, towards curved projecting surface240 of intermediate adjusting post 206.

Further, with reference to FIGS. 11-14, the engagement surface of eachwedge is oriented such that, if slid along the interfacing curvedprojecting surface of an adjusting post, the post will be urged towardthe engagement surface of the oppositely located wedge. The variouscross sectional views provided in FIGS. 11-14 show optical device 160 ina locked position wherein no relative movement of optical element 168about either the roll or tilt axis is permitted. The engagement surfacesof each respective wedge is in abutting contact with its interfacingcurved projecting surface on housing adjusting post 198 or intermediatemember adjusting post 206.

The method of imparting adjustment to the optical element about rollaxis 176 is as follows: referring first to FIG. 11, wedge 228 is firstmoved towards base 162 by rotation of lead screw 152, thereby providingclearance between surfaces 236 and 244. Lead screw 250 is then rotatedto move wedge 224 toward bottom wall 254 of body 218, thereby urgingintermediate member adjusting post 206 into clockwise rotation aboutroll axis 176. This rotation is continued until the optical element 168achieves its desired roll position about axis 176.

At this point, lead screw 252 is rotated in the direction opposite itsprior direction of rotation, thereby bringing wedge 228 away from base162, and surfaces 236 and 244 are brought into abutting contact. Withcurved surfaces 240 and 244 respectively abutting wedge surfaces 232 and236, intermediate member adjusting post 206 is trapped between wedges224 and 228, and optical element 168 locked thus locked against furtherrotation about roll axis 176. Conversely, should counterclockwiserotation of the adjusting post and thus the optical element about rollaxis 176 be desired, lead screw 250 is first rotated such that its wedge224 is driven towards base 162, creating clearance between surfaces 232and 240. Lead screw 252 is then rotated to draw its wedge 228 furtherfrom base 162, engagement surface 236 thereof driving surface 244 of theadjusting post rightward in its plane of motion. Once the desired rolladjustment of the optical element has been achieved, lead screw 250 isrotated in a direction opposite that of its prior rotation to draw wedge224 away from base 162 and bring wedge engagement surface 232 intolocking, abutting engagement with surface 240 of the adjustment post. Itwill be noted that regardless of the direction of rotation of adjustingpost 206 about roll axis 176, adjusting post 198 is carried with theadjusting post 206 because it is in sliding engagement with surfaces 214and 216 of cavity 210. It can thus be readily visualized that the planeof movement of housing adjustment post 198, which is perpendicular tothe plane of the drawing sheet, is rotated about roll axis 176 withmovement of adjustment post 206.

Similarly, with respect to adjustment of optical element 168 about tiltaxis 178, reference is made to FIG. 12. To impart clockwise rotation ofthe optical element 168 about tilt axis 178, lead screw 250 is firstrotated so as to drive wedge 226 towards base 162, thereby creatingclearance between surfaces 234 and 242. Lead screw 246 is then rotatedsuch that wedge 222 is drawn towards bottom wall 254, thereby urginghousing adjusting post 198 leftward in the drawing, and housing 184clockwise about tilt axis 178. Once the desired adjustment about tiltaxis 178 has been achieved, lead screw 250 is rotated in a directionopposite to that of its prior rotation, bringing wedge 226 away frombase 162 and bringing surface 234 of the wedge into locking engagementwith curved projecting surface 242 of the housing adjusting post.Conversely, counterclockwise rotation of housing 184 about tilt axis 178is achieved by first rotating lead screw 246 so as to force wedge 222upwards towards base 162, creating clearance between surfaces 230 and238. Screw 250 is then rotated to draw wedge 226 away from base 162, itsengaging surface 234 sliding against surface 242 of post 198, urging thepost rightward in FIG. 12.

Optical device 160 may be adjusted generally along the direction ofoutput axis 174 by means of shim(s) placed between bottom wall 254 andthe chassis mounting plate, in the manner described above with respectto optical device 20. It is envisioned that the range of adjustment ofthe optical center generally along the axis of output axis 174 whichshould be accommodated with device 160 is on the order of ±0.04 inch,with the shim(s) individually providing a linear resolution of about0.002 inch. Optical element 168 has a range of motion about its rollaxis of approximately ±20 milliradians (mrad), and the inventiveadjustment device provides the optical element with approximately 0.1mrad of angular resolution thereabout. Optical element 168 has a rangeof motion about its tilt axis of approximately ±10 mrad, and theinventive adjustment provides the optical element with approximately0.05 mrad of angular resolution thereabout.

Once the desired orientation about tilt axis 178 has been achieved, leadscrew 246 is rotated in a direction opposite to that of its priorrotation, drawing wedge 222 away from base 162 and bringing its surface230 brought into locking engagement with surface 238 of adjusting post198. With reference to FIG. 15, once optical element has been properlyadjusted and the adjusting posts locked are between their respectivepairs of opposed wedges, each wedge 222, 224, 226 and 228 is locked inposition within its respective recess 221 a-d to prevent theirinadvertent movement, which may alter the adjusted position of theoptical element. Locking screws 258 a-d, the tips of which respectivelyslidably engage angled surfaces 260 a-d of locking members 229 a-d, aretightened, thereby urging locking members 229 towards their adjacentwedges. Each wedge is thus compressed between the adjacent, abuttingsurfaces of its recess, and thereby locked in its adjusted position. Bythis means, backlash between lead screws 246, 248, 250 and 252 and theirrespective wedges 222, 224, 226 and 228 is eliminated as a factor bywhich the wedges may be allowed to move from their adjusted positions.Because the wedges are prevented from moving, movement of the adjustingposts, and thus of the optical element, relative to body 218 isprevented, and vibration-stability of the adjustment device is ensured.

It is to be noted that adjustment of optical element 168 about tilt axis178 does not necessarily involve any movement of intermediate memberadjusting post 206, which may remain locked in its previously adjustedposition. Further, it is to be noted that adjustment about the tilt androll axes need not be performed in any particular order, and adjustingposts 198 and 206 may be moved independently of one another to adjustthe optical element.

As in the first, second and third embodiments, thermal stability isachieved by using common, suitable materials, or materials havingsubstantially similar coefficients of thermal expansion in forming theflexure mechanisms, housing 184, intermediate member 192, base 162, andthe body and wedge elements of adjustment mechanism 164. The chassis towhich the device is attached may also be made of material common to thatof the components of device 160, or of a material having a substantiallysimilar coefficient of thermal expansion.

Adjustable optical device 160 is attached to its chassis- in by means offasteners (not shown) which extend through the chassis mounting plate(not shown) and are threadedly received in holes 262 provided in thefour corners of bottom wall 254 of body 218 . As shown best in FIGS. 9a,9 b and 10 c, three of these four corners of body 218 include integralportions 264 which are resiliently connected to the remainder of body218. A hole 262 is provided in each of portions 264, as well as in thecorner which is not provided with an integral, resilient portion 264,which is referred to herein as rigid corner 266. Strains associated withstresses within body 218 which result from its attachment to thechassis, or to possible relative thermal expansions and contractionsbetween the device and the chassis, are absorbed by the deflection ofportions 264, thereby allowing the remainder of body 218, the stabilityof which is relied upon for maintaining correct adjustment of opticalelement 168, to be remain isolated from such influences. Body 218 isrigidly affixed to the chassis through the attachment at rigid corner266.

While this invention has been described as having a various designs, thepresent invention can be further modified within the spirit and scope ofthis disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. An adjustable optical device comprising: anoptical element; a housing having an adjusting post fixed thereto, saidoptical element mounted to said housing, said housing adjusting posthaving a plane of movement; and an adjustment mechanism, said housingflexibly connected to said adjustment mechanism, said adjustmentmechanism comprising a moving adjusting member in sliding engagementwith said housing adjusting post, one of said adjusting member and saidhousing adjusting post comprising a wedge, wherein said housingadjusting post is urged into movement in its said plane of movement inresponse to relative movement between said adjusting member and saidadjusting post, whereby the orientation of said optical element relativeto said adjusting mechanism is adjusted by movement of said movingadjusting member.
 2. The adjustable optical device of claim 1, whereinsaid housing has substantially perpendicular tilt and roll axes, one ofsaid tilt and roll axes substantially perpendicular to said housingadjusting post plane of movement, and further comprising a base, saidhousing having movement relative to said base about said one of saidtilt and roll axes, said adjusting mechanism attached to said base. 3.The adjustable optical device of claim 2, wherein said optical elementhas an optical center and said tilt and roll axes intersect at saidoptical center.
 4. The adjustable optical device of claim 2, furthercomprising an intermediate member disposed between said housing and saidbase, said intermediate member having an adjusting post fixed thereto,said intermediate member adjusting post having a plane of movement, theother of said tilt and roll axes substantially normal to saidintermediate member adjusting post plane of movement, said intermediatemember flexibly connected to said housing and to said base, said housinghaving movement relative to said intermediate member about said one ofsaid tilt and roll axes, said housing having movement relative to saidbase about both said tilt and roll axes.
 5. The adjustable opticaldevice of claim 4, wherein said moving adjusting member is a firstmoving adjusting member and said wedge is a first wedge, and saidadjustment mechanism further comprises a second moving adjusting memberin sliding engagement with said intermediate member adjusting post, oneof said second adjusting member and said intermediate member adjustingpost comprising a second wedge, and wherein said intermediate memberadjusting post is urged into movement in its said plane of movement inresponse to relative movement between said second adjusting member andsaid intermediate member adjusting post, whereby the orientation of saidoptical element relative to said base is adjusted by movement of saidsecond moving adjusting member.
 6. The adjustable optical device ofclaim 5, wherein said housing adjusting post plane of movement is fixedrelative to said intermediate member adjusting post plane of movement.7. The adjustable optical device of claim 6, wherein said housingadjusting post and said intermediate member adjusting post extendthrough said base.
 8. The adjustable optical device of claim 7, whereinsaid intermediate member adjusting post has a longitudinal axis, saidintermediate member adjusting post provided with a cavity which extendsalong its said longitudinal axis and laterally through said intermediatemember adjusting post, said housing adjusting arm disposed within saidcavity.
 9. The adjustable optical device of claim 8, wherein said cavityis provided with opposed interior side walls, said housing adjustingpost in sliding engagement with said opposed side walls, whereby saidhousing adjusting post plane of movement is moved with said intermediatemember adjusting post in said intermediate member adjusting post planeof movement.
 10. The adjustable optical device of claim 9, wherein saidhousing adjusting post is provided with oppositely facing first andsecond side surfaces, said first moving adjusting member is in selectivesliding engagement with one of said housing adjusting post first andsecond side surfaces, and further comprising a third moving adjustingmember in selective abutting contact with the other of said housingadjusting post first and second side surfaces, whereby said housingadjusting post is locked between said first and third adjusting members,relative movement between said housing and said intermediate memberthereby restrained.
 11. The adjustable optical device of claim 10,wherein said intermediate member adjusting post is provided withoppositely facing first and second side surfaces, said second movingadjusting member is in selective sliding engagement with one of saidintermediate member adjusting post first and second side surfaces, andfurther comprising a fourth moving adjusting member in selectiveabutting contact with the other of said intermediate member adjustingpost first and second side surfaces, whereby said intermediate memberadjusting post is locked between said second and fourth adjustingmembers, relative movement between said intermediate member and saidbase thereby restrained.
 12. The adjustable optical device of claim 5,wherein said first and second moving adjusting members respectivelycomprise first and second rotating lead screws, and said first andsecond wedges are respectively threadedly engaged on first and secondrotating lead screws, said wedges moved in response to rotation of saidlead screws.
 13. The adjustable optical device of claim 5, wherein saidhousing and said intermediate member are connected through a firstelastically yieldable flexure element having one end which is attachedto said housing and another end opposite its said one end which isattached to said intermediate member.
 14. The adjustable optical deviceof claim 13, wherein said first flexure element is substantially flat.15. The adjustable optical device of claim 13, wherein said intermediatemember and said base are connected through a second elasticallyyieldable flexure element having one end which is attached to saidintermediate member and another end opposite its said one end which isattached to said base.
 16. The adjustable optical device of claim 15,wherein said second flexure element is substantially flat.
 17. Anadjustable optical device comprising: an optical element; a base havinga substantially spherical inner surface; a housing, said optical elementdisposed within said housing, said housing having a substantiallyspherical outer surface engaged with said base substantially sphericalinner surface, said housing provided with a driven surface, said housinghaving a tilt axis and a roll axis about which the orientation of saidhousing relative to said base is adjusted; and an adjustment devicehaving an operating position relative to said base, said adjustmentdevice comprising a moving adjusting mechanism which includes a drivingsurface, said driven and driving surfaces engaged in said operatingposition, said adjusting mechanism comprising a lever operativelyconnected to said driving surface, said lever having two substantiallyperpendicular degrees of movement, wherein movement of said housingabout one of its said tilt and roll axes is in response to movement ofsaid lever along one of its said degrees of movement.
 18. The adjustableoptical device of claim 17, further comprising a cover having asubstantially spherical inner surface engaged with said housingsubstantially spherical outer surface, said housing releaseably clampedbetween said cover and said base.
 19. The adjustable optical device ofclaim 17, wherein said tilt axis and said roll axis intersect at thespherical center of said housing outer surface.
 20. The adjustableoptical device of claim 19, wherein said optical element has areflective surface, said housing outer surface spherical center locatedon said reflective surface.
 21. The adjustable optical device of claim17, wherein said adjusting mechanism comprises two perpendicularlyfacing moving wedges, said wedges in sliding contact with said lever,said lever moved in one of its two degrees of movement in response tomovement of a said wedge.
 22. The adjustable optical device of claim 21,wherein said adjusting mechanism comprises a lead screw threadedlyengaged with each said wedge, each said wedge moved in response torotation of its respective said lead screw.
 23. The adjustable opticaldevice of claim 22, wherein each said lead screw is provided with meansfor indicating that the said lead screw has been rotated through apredetermined angle.
 24. The adjustable optical device of claim 17,wherein said adjustment device is removably located in its saidoperating position.
 25. An adjustable optical device comprising: anoptical element; a base; a housing, said optical element mounted in saidhousing, said housing coupled to said base and in substantiallysurface-to-surface contact therewith, said housing having at least onedegree of movement relative to said base, whereby the orientation ofsaid optical element relative to said base is adjusted by the movementof said housing in said at least one degree of movement, said housingbeing selectively locked to said base; and an adjustment devicedetachably connected to said base and having a moving adjustingmechanism, and wherein, when said adjustment device is connected to saidbase, said adjusting mechanism is operatively connected to said housingto move said housing in its said at least one degree of movement inresponse to movement of said adjusting mechanism, said housing remainingselectively locked to said base when said adjustment device is detachedfrom said base.
 26. The adjustable optical device of claim 25, whereinsaid housing has two degrees of movement, one of said housing degrees ofmovement about a tilt axis which extends through said optical element,the other of said housing degrees of movement about a roll axis whichextends through said optical element, said tilt and axes substantiallyperpendicular to each other.
 27. An adjustable optical devicecomprising: an optical element; a base; a housing, said optical elementmounted in said housing, said housing coupled to said base and havingtwo degrees of movement relative to said base, one of said housingdegrees of movement being about a tilt axis which extends through saidoptical element, the other of said housing degrees of movement beingabout a roll axis which extends through said optical element, said tiltand roll axes substantially perpendicular to each other, whereby theorientation of said optical element relative to said base is adjusted bythe movement of said housing in at least one said degree of movement,said housing being selectively locked to said base; a stem fixed to saidhousing, said stem extending from said housing into said base, movementof said stem relative to said base imparted to said housing, wherebysaid housing is moved about one of said tilt and roll axes; and anadjustment device detachably connected to said base and having a movingadjusting mechanism, and wherein, when said adjustment device isconnected to said base, said adjusting mechanism is operativelyconnected to said housing to move said housing in at least one saiddegree of movement in response to movement of said adjusting mechanism,said housing remaining selectively locked to said base when saidadjustment device is detached from said base.
 28. The adjustable opticaldevice of claim 27, wherein said adjusting mechanism comprises areceptacle and a lever, said stem received in said receptacle, saidreceptacle attached to said lever, said lever having two substantiallyperpendicular degrees of movement, said housing moved about one of saidtilt and roll axes in response to movement of said lever in one of itssaid degrees of movement.